"It's totally anonymous," was how one commenter put it in Bitcoin's forums in June 2013. As recently as 3 years ago, it seemed that anyone could buy or sell anything with Bitcoin and never be tracked, let alone busted if they broke the law. If you for whatever reason don't want to use Trezor, cold storage may be a good compromise between the convenience of a hardware wallet and the security of a paper wallet.Bitcoin, the Internet currency beloved by computer scientists, libertarians, and criminals, is no longer invulnerable. But if you hold a significant amount of bitcoins you don't want to risk getting it stolen. Running a cold storage may seem like an annoyance and quite difficult to set up.
The transaction will then be sent to ever Bitcoin node on the network and eventually mined by a miner. Go back to the online watch-only wallet and open Tools -> Load transaction -> From file again.Ī window with the signed transaction detail will show up again.Ĭheck the corresponding values and if it's alright click " Broadcast". The transaction is now ready to be broadcasted on the network.Ĭlick " Save" and save the new file to your USB stick again.
Upon signing the transaction have a look at the field " Transaction ID" which changed from " unknown" to a seemingly random string. You may be prompted to type in the password if your wallet is secured with one (it's recommended). The transaction window will pop up again but this time with an option to sign the transaction. Now go back to your offline computer and go to Tools -> Load transaction -> From file and select the file from the USB stick. On your watch-only online wallet, go to " Send" tab, fill in transaction details and click " Preview".Ī transaction window will pop up with details about the transaction, such as inputs, outputs, the amount and the fee.Ĭlick " Save" and save the " unsigned.txn" file to your USB stick. Go to " Receive" tab and send some money to a generated wallet address of the offline wallet. Write it down on a piece of paper and store it somewhere safe!īut before you can start using it you need to load it with some bitcoins. You'll be presented with a mnemonic code consisting of 12 words. Make sure " Create a new seed" is selected and go to the next step. We'll use a " Standard wallet" but you can use any type except for " Watch Bitcoin addresses". Let's call it " offline" for the purpose of the tutorial.Ĭhoose the wallet type. Open Electrum, click File -> New/Restore and create a name for the wallet. In this tutorial, I'll be using the latest Electrum wallet 2.8.2 on both computers. This wallet can be " online" because it doesn't contain any private keys. You'll also have to run a " watch-only" wallet on another computer that is only able to view transaction history and outputs (wallet addresses) of the cold storage but can't spend them. To set up one, you need an (old) computer and a wallet software that is able to import, sign and export transactions. It can only be accessed physically which makes it very secure. If you care about security and don't feel like buying Trezor, you may want to keep your bitcoins in an offline wallet also known as cold storage.Ĭold storage is a wallet that isn't connected to any network thus it's not vulnerable to online attacks.